Separation of acetone, butanol and ethanol (ABE) from dilute aqueous solutions by silicalite-1/PDMS hybrid pervaporation membranes

To study the effects of different factors on the separation of acetone, butanol, and ethanol (ABE) from ABE-water solutions by pervaporation with silicalite-l/polydimethylsiloxane (PDMS) hybrid membranes, the adsorption of ABE in the silicalite-1 in acetone-butanol-water solution and ethanol-butanol-water solution was firstly investigated and then the separation of ABE from binary aqueous solutions at different feed concentrations and temperatures was examined. Experimental results showed that butanol could be preferentially adsorbed on silicalite-1 and the permeability of acetone through the membrane was the highest, followed by butanol and ethanol, which was not consistent with the predictions based on the experimental results of adsorption and membrane swelling measurement. This could be explained by Hansen solubility parameters for the component and polymer interactions (delta(m,c)) and for the organic solvent and water interactions (delta(w,i)). In the separation of ABE-water solution by the silicalite-1/PDMS hybrid pervaporation membranes, acetone and ethanol could promote ABE transport through membrane and block water permeation, and the membrane performance could be significantly affected by vacuum pressure in the permeate side. (C) 2011 Elsevier B.V. All rights reserved.